PURING AND/OR SYMMETRICAL GOLF SHAFTS

Why do shafts need puring?

Like snowflakes, no two golf shafts are exactly the same. Every shaft contains irregularities in straightness, roundness and stiffness that are inherent to the manufacturing process. These structural inconsistencies can negatively or positively affect a shaft’s performance, depending on how the shaft is aligned in the club head. Puring or making your golf shafts symmetrical, locates the most stable orientation in any shaft, sometimes called the spine. The process works on any golf shaft, regardless of its material; steel, or graphite. Once located, the spine of the golf shaft is positioned into the club head, so that the spine is facing the target.

Here is our, www.golfclub-technology.com’s, KISS take on this subject, and it has worked for us for over ten years.

The best and easiest way to explain spine aligning, puring, flo-ing, or symmetrical shafting, is the process of finding the natural and least point of resistance of a golf shaft.

By spining your shaft, the clubface will open and close when you want it to, not when the shaft wants it to. Simple eh?

Using sensitive data-acquisition sensors, in our case, a spine alignment finding tool, the shaft alignment process analyzes the structural irregularities that exist to some degree in every golf shaft and locates the shaft’s most stable orientation. We mark it, and we call it- THE SPINE.

This process of club assembly, deemed in compliance with USGA standards and rules, aligns the shaft so that each club bends in the direction it should, straight down the target line.

WELDED STEEL TUBING – Today, just about all steel shafts are made by bending sheet steel into a tubular form and welding it. The major manufacturers of steel shafts seem to have figured out how not to let the seam interfere with directional uniformity of stiffness. Do steel shafts need puring? Definitely; Steel shafts are made by heating a flat piece of steel and wrapping it around a template called a mandrel. The ends of the steel are welded together to form what is called a weld seam. The location of this weld seam greatly affects the way the shaft performs. Straightness and roundness are also an issue in mass-produced steel golf shafts, and the puring process takes all of these factors into account.

SHEET-WRAPPED GRAPHITE - (This is also referred to as "flag-wrapped".) This approach involves taking a sheet of woven carbon fibers and wrapping it around a rod called a "mandrel". They are held together in a sheet by being impregnated with a resin. Several sheets of pre-preg, with the fibers in different directions, are wrapped onto the mandrel in multiple layers. The number of layers of each kind (and the properties of the fibers) will determine the bending and torque profile of the shaft. Sheets that are wrapped onto the mandrel have a beginning and an end. The discontinuity at the beginning and end mean that the shaft is slightly stiffer where the extra layer is. Hence there is a potential for a spine; some directions have more fiber layers than others. In fact, sheet-wrapped graphite shafts do tend to have more spine than other types of shafts.

FILAMENT WOUND GRAPHITE - These shafts don't use a pre-preg. Instead, the individual fibers (filaments) are wound in a spiral onto a mandrel. Actually, they are more woven than wound; spirals in both directions are applied simultaneously and woven together. The process involves a pretty intricate machine to weave the fibers. After they are wound in place, they are resin-impregnated and cured. The result is generally remarkably free of spine, but we have managed to find a spine all the time. There are other disadvantages of filament-wound shafts, but consistency of directional stiffness (and consistency of specs in general) is a definite advantage.






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